Conventionally some image forming apparatuses include a processing apparatus made up of a plurality of processing units for extended features, in addition to a main body (main apparatus) of the apparatus to perform image forming processing to a sheet. Exemplary processing units include a high-capacity sheet feeding apparatus to store sheets therein and feed a sheet to the main body of the apparatus, and a post-processing apparatus to perform post-processing to a sheet subjected to image forming processing by the main body of the apparatus. If a first processing unit and a second processing unit are disposed on mutually opposed lateral faces of the main body of the apparatus, then the footprint of the image forming apparatus will be increased.
Then, an image forming apparatus is known, including a sheet-output tray (hereinafter this may be simply called an output tray) on a sheet-feeding tray (hereinafter this may be simply called a feeding tray) (see Patent Literature 1, for example). This conventional image forming apparatus includes the feeding tray and the output tray that are vertically stacked, whereby the footprint of the apparatus can be decreased as compared with the case where the feeding tray and the output tray are disposed on different lateral faces of the main body of the apparatus.